1. Field of the Invention
This invention relates generally to a method of catalyzing heterogeneous ionic (polar) reactions in which the reactants are located in different liquid phases of differing polarity. More specifically, but not by way of limitation, the invention relates to a method for improving the reaction between a plurality of reactants in an environment in which one of the reactants is located predominantly in an aqueous liquid phase which is substantially immiscible with a contiguous organic liquid phase in which a second reactant is predominantly located so that significant reaction can only occur at the interface of the phases or by transfer of a functional group from one phase into another phase.
2. Description of the Prior Art
The organic quaternary salts of the Group VA elements of the Periodic Table of the Elements are known to be, in general, very stable, strong bases which are highly ionized in aqueous solutions to form a stable cation containing the pentavalent element bonded to its hydrocarbon substituents by strong covalent linkages. These quaternary salts have recently been found to be even more highly reactive in many ionic reactions than the corresponding sodium and potassium salts. It is also recognized that by adequately adjusting the configuration and length of the organic portions of the quaternary salt molecule, these compounds can be made to be readily soluble in organic solvents.
The possibility that the quaternary salts of the general type under discussion may be employed in a catalytic capacity in one reaction system has been explored and confirmed by Oxenrider et al. In their U.S. Pat. No. 3,297,634, these workers disclose the use of certain quaternary ammonium, phosphonium and arsonium salts for catalyzing the cyclization of a phosgene derivative of a bisphenate salt to produce a cyclic dicarbonate. The catalytic activity of the catalyst is postulated to arise from a mechanism in which the catalyst displaces the cationic portion of the phosgene derivative so as to render the derivative as a whole more soluble in a water-insoluble organic medium in which the desired cyclization transpires. The function of the quaternary salt is thus deemed to be that of solubilizing the reaction product of the phosgene-bisphenate reaction in an organic medium which provides the required environment for the occurrence of intramolecular cyclization. There does not appear to be involved in this catalysis any transfer across a phase interface of a functional group derived from a first reactant located in one liquid phase to a second reactant located in a second liquid phase with the quaternary salt acting as the acceptor of the functional group in the first phase and the donor of the functional group in the second phase.